Closed the trash and waste glitch

Because of massive abuse of an exploit with trash to achieve hyper growth, I have made some changes to the market system.

The amount of trash/wastewater/radioactive waste you can buy is now limited to 30% of you total company assets.

Also the waste products which are already being shipped to you are also already accounted in this 30%, locking shipments no longer serves a purpose.

Therefore I will also re-allow the shipping speed to go from 0% to 100% again.